Epidermolysis Bullosa MCQ Quiz | Hereditary Disorders

Welcome to this specialized multiple-choice quiz on Epidermolysis Bullosa (EB), a group of rare, inherited connective tissue disorders. Designed for MBBS students, this quiz will test your understanding of the genetic, pathophysiological, clinical, and diagnostic aspects of the different EB subtypes. You will encounter questions on the specific proteins and genes involved (like Keratins, Collagen VII, and Laminin-332), the corresponding levels of skin cleavage, characteristic clinical signs such as “mitten” deformities, and major complications like squamous cell carcinoma.

This assessment contains 25 questions to help you consolidate your knowledge on this challenging topic. After submitting your answers, you will receive your score and a detailed review of each question. You can also download a complete list of all questions and their correct answers in PDF format for future reference.

1. Which structural protein is primarily affected in the most common forms of Epidermolysis Bullosa Simplex (EBS)?

Collagen VII Laminin-332 Keratin 5 and 14 Plectin

2. What is the mode of inheritance for the severe, generalized form of Recessive Dystrophic Epidermolysis Bullosa (RDEB)?

Autosomal Dominant Autosomal Recessive X-linked Recessive Mitochondrial Inheritance

3. The severe Herlitz type of Junctional Epidermolysis Bullosa (JEB) is caused by null mutations in genes encoding which of the following proteins?

Laminin-332 Collagen XVII Integrin α6β4 Type IV Collagen

4. The presence of “mitten” deformities (pseudosyndactyly) of the hands and feet is a classic and debilitating feature of which type of EB?

Epidermolysis Bullosa Simplex Junctional Epidermolysis Bullosa Recessive Dystrophic Epidermolysis Bullosa Kindler Syndrome

5. In Epidermolysis Bullosa Simplex, where does the blister cleavage plane occur?

Within the basal keratinocytes (intraepidermal) Within the lamina lucida Below the lamina densa (subepidermal) Within the papillary dermis

6. A skin biopsy for immunofluorescence antigen mapping from a patient with Dystrophic Epidermolysis Bullosa would show a cleavage plane located where?

Intraepidermal Within the lamina lucida Below the lamina densa of the basement membrane Within the granular layer of the epidermis

7. Mutations in the COL7A1 gene, which encodes for type VII collagen, are responsible for which major type of EB?

Epidermolysis Bullosa Simplex Junctional Epidermolysis Bullosa Dystrophic Epidermolysis Bullosa Kindler Syndrome

8. Patients with severe, generalized Recessive Dystrophic EB (RDEB) have a significantly increased risk of developing which type of malignancy?

Melanoma Basal Cell Carcinoma Aggressive Squamous Cell Carcinoma Cutaneous T-cell Lymphoma

9. In Junctional Epidermolysis Bullosa (JEB), the tissue separation or blister formation occurs within which layer of the basement membrane zone?

Lamina densa Sub-lamina densa Lamina lucida Basal keratinocyte cytoplasm

10. Kindler syndrome, a rare form of EB, is caused by mutations in the FERMT1 gene, which encodes for which protein?

Plectin Kindlin-1 Laminin-332 Keratin 14

11. A newborn presents with widespread blistering. A biopsy shows a subepidermal split and immunofluorescence microscopy reveals absent staining for Type VII collagen. What is the most likely diagnosis?

Epidermolysis Bullosa Simplex, Dowling-Meara type Junctional Epidermolysis Bullosa, Herlitz type Dystrophic Epidermolysis Bullosa Staphylococcal Scalded Skin Syndrome

12. Which of the following is a cornerstone of daily management for all severe forms of EB?

Systemic corticosteroid therapy Prophylactic broad-spectrum antibiotics Meticulous wound care and prevention of trauma Routine skin grafting

13. Chronic anemia in patients with severe EB is most often due to:

Autoimmune hemolysis Bone marrow suppression from chronic inflammation Vitamin B12 deficiency from malabsorption Iron deficiency from chronic blood loss and poor intake

14. Esophageal strictures requiring repeated dilation are a common and serious complication, particularly in which type of EB?

Localized Epidermolysis Bullosa Simplex Recessive Dystrophic Epidermolysis Bullosa Dominant Dystrophic Epidermolysis Bullosa Kindler Syndrome

15. Epidermolysis Bullosa Simplex with muscular dystrophy is a rare variant caused by mutations in the gene encoding which protein?

Dystrophin Keratin 5 Plectin Collagen XVII

16. What is considered the gold standard for accurately sub-typing Epidermolysis Bullosa?

Clinical presentation alone Serum antibody testing Complete blood count and metabolic panel Immunofluorescence antigen mapping and/or transmission electron microscopy

17. A couple, both phenotypically normal, has a child with Autosomal Recessive Dystrophic EB. What is the recurrence risk for this condition in their future children?

50% 25% 75% Virtually 0%

18. The formation of milia (small white cysts) within healing blisters is a characteristic finding in which type of EB?

Dystrophic Epidermolysis Bullosa Epidermolysis Bullosa Simplex Junctional Epidermolysis Bullosa All types of EB

19. Corneal erosions, scarring, and symblepharon are significant ocular complications most frequently seen in which two major types of EB?

Simplex and Kindler Junctional and Dystrophic Simplex and Dystrophic Simplex and Junctional

20. The Dowling-Meara variant of Epidermolysis Bullosa Simplex is characterized by a herpetiform (clustered) arrangement of blisters and is known for which clinical course?

Progressive worsening throughout life Fatal outcome in early infancy Significant improvement with age Complete resolution by puberty

21. What is the primary function of Type VII collagen in the skin?

To provide tensile strength within keratinocytes To form the main structural component of the lamina densa To form anchoring fibrils that secure the epidermis to the dermis To link hemidesmosomes to the underlying basement membrane

22. Microstomia, ankyloglossia, and extensive dental caries are common manifestations affecting which system in severe EB?

Ocular Gastrointestinal Oral and dental Genitourinary

23. Novel therapeutic approaches under investigation for RDEB often involve gene therapy targeting the restoration of which gene?

KRT5 LAMB3 COL7A1 PLEC

24. The non-Herlitz (generalized atrophic benign) form of Junctional EB is less severe and most commonly associated with mutations in genes for:

Type XVII collagen or Laminin-332 Keratin 5 and 14 Plectin Kindlin-1

25. Which type of EB is characterized by photosensitivity, poikiloderma, and skin blistering, particularly in infancy?

Dystrophic EB Junctional EB EB Simplex Kindler Syndrome